// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/gl/gl_fence.h"

#include "base/compiler_specific.h"
#include "build/build_config.h"
#include "ui/gl/gl_bindings.h"
#include "ui/gl/gl_context.h"
#include "ui/gl/gl_fence_arb.h"
#include "ui/gl/gl_fence_egl.h"
#include "ui/gl/gl_fence_nv.h"
#include "ui/gl/gl_gl_api_implementation.h"
#include "ui/gl/gl_implementation.h"
#include "ui/gl/gl_version_info.h"

#if defined(OS_MACOSX)
#include "ui/gl/gl_fence_apple.h"
#endif

namespace gfx {

GLFence::GLFence()
{
}

GLFence::~GLFence()
{
}

bool GLFence::IsSupported()
{
    DCHECK(GetGLVersionInfo());
    return g_driver_gl.ext.b_GL_ARB_sync || GetGLVersionInfo()->is_es3 || GetGLImplementation() == kGLImplementationDesktopGLCoreProfile ||
#if defined(OS_MACOSX)
        g_driver_gl.ext.b_GL_APPLE_fence ||
#else
        g_driver_egl.ext.b_EGL_KHR_fence_sync ||
#endif
        g_driver_gl.ext.b_GL_NV_fence;
}

GLFence* GLFence::Create()
{
    DCHECK(GLContext::GetCurrent())
        << "Trying to create fence with no context";

    scoped_ptr<GLFence> fence;
    // Prefer ARB_sync which supports server-side wait.
    if (g_driver_gl.ext.b_GL_ARB_sync || GetGLVersionInfo()->is_es3 || GetGLImplementation() == kGLImplementationDesktopGLCoreProfile) {
        fence.reset(new GLFenceARB);
#if defined(OS_MACOSX)
    } else if (g_driver_gl.ext.b_GL_APPLE_fence) {
        fence.reset(new GLFenceAPPLE);
#else
    } else if (g_driver_egl.ext.b_EGL_KHR_fence_sync) {
        fence.reset(new GLFenceEGL);
#endif
    } else if (g_driver_gl.ext.b_GL_NV_fence) {
        fence.reset(new GLFenceNV);
    }

    DCHECK_EQ(!!fence.get(), GLFence::IsSupported());
    return fence.release();
}

bool GLFence::ResetSupported()
{
    // Resetting a fence to its original state isn't supported by default.
    return false;
}

void GLFence::ResetState()
{
    NOTIMPLEMENTED();
}

} // namespace gfx
